Originally published in Sun Sailor.
In August 2018, during a routine Three Rivers Park District boat inspection, an unusual plant was discovered on a boat leaving Medicine Lake at the access in French Regional Park. Within hours, the Department of Natural Resources Aquatic Invasive Species Rapid Response team was diving the waters of Medicine Lake to gather more information. Unfortunately, this plant was the first discovery of starry stonewort within the metro area.
Starry stonewort is an aquatic invasive species that is a bushy, bright green macro-algae that forms dense mats making boating, fishing and swimming difficult. It’s named for the small, white, star-shaped bulbils that distinguish it.
Three Rivers Park District’s Water Quality team and DNR staff members surveyed all of Medicine Lake and found starry stonewort in approximately 14 acres of the lakebed in the area west of the French Regional Park boat launch. The two agencies developed a rapid response plan and treated the lake every other week for the rest of the 2018 season. Treatments are expected to start again in July, with the DNR funding both seasons of lake treatments.
The Bassett Creek Watershed Management Commission, whose jurisdiction includes Medicine Lake, received a grant from Hennepin County to purchase a watercraft decontamination station that is used at the French Regional Park boat launch and staffed by Three Rivers inspectors. This year, Plymouth has closed the West Medicine Lake boat launch and is helping fund additional staff hours for watercraft inspections at the French Park boat launch. In addition, Hennepin County has requested a mobile unit for the French Park boat launch that gives boat owners the knowledge and resources to decontaminate their own boats before leaving the park.
In 2018, Three Rivers Park District performed nearly 21,000 watercraft inspections. Recently, I talked with our watercraft inspectors at Baker Park Reserve. They shared that the two most common issues occur when people have recently purchased a used watercraft or trailer and aren’t aware that it contains aquatic invasive species or when people forgot to drain their boat’s live well when they exited a lake. Watercraft inspectors’ role in these situations is to help educate boaters.
Following the clean-in and clean-out best practice from the DNR is key to containing the spread of aquatic invasive species. This includes cleaning your watercraft, draining all water and properly disposing of unwanted bait.
I want to thank the boating public for their patience during the boat inspection process and recognize park district staff and our partners for their meaningful work on this issue. To learn more about the efforts of park district water quality staff to maintain and improve the health of the region’s water bodies, check out our latest podcast episodes on water quality at the Wandering Naturalist Podcast.